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Nov. 19, 1929.

J. G. GRAY GYROSGOPIC APPARATUS Filed July 1, 1927 3 Sheets-Sh'eet Nov.19, 1929. J. G. GRAY GYROSCOPI C APPARATUS Filed July 1, 1927 3Sheets-Sheet 2 ILAAAAA vvvvvvv..

Nov. 19, '1 929. J. G. GRAY GYROSCOPIC APPARATUS 3 Sheets-Sheet FiledJuly 1,. 1927 Q9.

Patented Nov. 19, 1929 stares GYEOSCOPIG APPARATUS Application died July1, .1987, Serial No. 202,850, and in Great Britain duly 8,1938.

This invention relates toimproved gyroscopic a paratus for defining thevertical on moving odies or vehicles such as ships, airships andaeroplanes, and for stabilizing instruments of recision when mounted onsuch bodies or vehicles.

The principle underlying the a%)aratus of the invention is described inmy atent No.

' 1,442,7 99 of 23rd January, 1923, and involves 1c the attachment of agyroscope or gyroscopes to the vehicle by means of frames and pivots orthe equivalent in such manner as to constitute a gyroscopic stabilizerpresenting, athwart the vehicle, a component of angular in momentum orspin, whose amount is the prodnot of the mass of the system carried onfore and aft pivots which attach the. system to the vehicle, thedistance of the centre of gravity of the system below the line of saidpivots, and the speed of the vehicle relatively to the medium in whichit moves; provided that the direction or sense of this spin is clockwiseas viewed from the starboard side of the vehicle, the pivoted system isnot discompany turning movements of the vehicle.

In the accompanying drawings, which illustrate several forms of theinvention, Fig. 1 is an elevation and Fig. 2 a plan embodying one simpleconstruction. Fig. 3 is an elevation illustrating an alternativeconstruction. Fig. 4 is an elevation and Fig. 5 a plan showing yetanother alternative. Fig. 6 is a plan showing a variation of theinvention. Figs. 7 and 8 are, respectively, a plan and an elevationshowing a further modification. Fig. 9 is an elevation showing anothermodification. Fig. 10 is a view in detail of means of dampingoscillations. Fig. 11 is an elevation showing a modified constructionaccordmg to the invention. Fig. 12 is a detailed view showing theattachment of a compensating gyroscope. Referring to Figs 1 and 2, agyroscope 1 is pivoted vertically at 2, 2 to a frame 3, or theequivalent. The frame 3 is pivoted horizontally at 4, 4 to supports '5,5 which are attached rigidly to the movingvehicle. The centre of gravityof the gyroscope lies in the line of the pivots 2, 2 and, when the frame3 is vertical, the centre of gravityof the sys turbed by the centrifugalcouples which ac-.

tem carriedon the pivots 4, 4 lies vertically below the line of pivots4, 4. Horizontalspindles 7 7' are driven rapidly in the direction ofspin of'the gyroscope flywheel, conveniently directly from the spindleof-the flywheel of the gyroscope by means of reduction gearing containedin the casings 6, 6', and to these spindles 7, 7' are attached systemsof vanes 8, 8; 8, 8'. The vanes move at high speed through the air and,as a result, a reaction couple is applied to the casing of thegyroscope, which couple is in the plane of the flywheel, or in aparallel plane, and is counter-clockwise as viewed from the starboardside of the vehicle. The gyroscope is centralized with respect to theframe 3 by meansof two springs 9, 9, or the e uivalent, as shown. Theresting position of t a device is one in which the frame is vertical,with the axis of the gyroscope horizontal and at right so angles to theframe 3. Now suppose the device set up on a moving vehicle with thepivots 4, 4 lying fore and aft with respect to the vehicle. Let thedirection of motion of the vehicle be that indicated by the straightarrow, and the direction of spin of the gyroscope that indicated by thecurved arrow, in Fig. 1. Sup ose the device in the resting position, andet the vehicle execute a turning movement with angular so speed 1/1. Thecentrifugal couple experienced by the device is MV it, where M is themass of the system carrie on the pivots 4, 4, V is til the speed of thevehicle and hthe distance of the centre of gravity of the system belowas the axis of the pivots 4, 4. This couple causes the roscope to turnon the pivots 2, 2 with angu ar speed 0 given by I I S i gr 1 89 Where Iis the momentof inertia of the flywheel of the gyroscope and m is itsangular velocity. Further, with the direction of spin of theyroscopeindicated by the curved arrow, a as the same direction as 1,0,and hence if MVk=Im, the gyroscope keeps time with the vehicle and theframe remains vertical.

As already explained, the system is provided with gravity control withrespect to the pivots 4, 4. The amount of thecontrol may )e varied byadjustment of amass 10, whic can be moved up or down by turning a screw11 which is provided with a milled head 12. The function of the rotatingvanes is to damp out an precessional motion of the gyroscope. I theframe is deflected .with respect to the vertical on the pivots 4, 4, thegyroscope processes; the frame oscillates --to andfro on the fore-andaft pivots 4, 4, and the gyroscope oscillates to and fro on thepivots-2, 2. It is convenient to choose the springs 9, 9 so that theamplitudes of the latter oscillations are much larger than those of theformer. As already explained, in consequence of'the rotation of thevanes in the to mate with the screw 11 so that when the air there isapplied to the casing of the roscopea couple in the plane of the flyweel and in the direction opposed to that in which.

the wheel is rotating.-. As the frame turns on the pivots 4, 4, thisreaction couple dam s out the motion. The couple, it will be 0 served,has a component about the pivots 4, 4 when the gyroscope is displaced onthe pivots 2, 2 relatively to the frame3. vWith the direction ofrotation ofthe vanes specified the couple acts so as to oppose themotion of the frame on the pivots 4, 4; that is,-the precessional motionof the gyrosco e on the pivots 2, 2 is delayed, with the resu t that.the oscillations of the gyroscope are damped out.

The mass 10 is internally screw-threaded screw is turned the mass movesup or down according to the direction in which the screw is turne Themass 10 is provided with projections which slidably engage a guide baras shown. By moving the mass 10 up or down the value of h in theforegoing equation is diminished or increased. The mass is adjusted inaccordance with the speed of the vehicle so that the equation M V h=lmis satisfied.

An alternative construction is shown in elevation in Fi 3. The gyroscope1 provided as before wit sets of driven vanes 8, 8 is rigidly'attachedto the frame 3, or the equiv alent. As before, a displaceable mass 10 ismounted on the frame 3. The frame 3 is pivotally sustained in asurrounding frame 3' by fore-and-aft pivots 2, 2', as shown, andthisframe 3 is connected in turn to the vehicle by means of vertical pivots4, 4' The frame 3" is rendered stable with respect to the moving vehiclewith the pivots 2', 2 lying fore and aft with respect to thevehicle, bymeans of centralizing springs in the manner already described. The frame3, with its carried system is provided with gravity control with respectto the pivots 2', 2', the amount of'this control being determined by theequation M Vh=lw, as already explained. The direction of motion of thevehicle being that shown by the straight arrow, and the direction ofspin of the gyroscope flywheel, and of rotation of the vanes 8, 8 beingthat indicated by I the curved arrow, the equilibriumposition of theframe 3.. is that in which it is upright with the frame 3' lying'foreandaft with respect isturbance. The construction shown in igs. 1 and 2 is,for this reason, to be preferred..." I

A further form of the invention is shown in elevation and in lan inFigs. 4 and 5. A gyroscope 1 is attac ed to a vertical frame 3,

or the equivalent by means of vertical pivots 2, 2 and the frame isattached to uprights 5, 5

by fore-and-aftpivots 4, 4. Mounted on the frame 3 is a displaceablemass 10 capable of up and-down movement as already described. The upperpivot 2 is prolonged and secured to the boss of an arm 13 terminatin ina. brush-holder or a contact making roller 19- the axis of spin of thegyroscope is perpen-- dicular to the frame 3 and the contact roller 19rests on the strip of insulating material 16. Mounted on the frame 3 isa reversible electric motor 6 to the shaft of which motor is attached asystem of vanes 8 as shown. When the motor is energized, the vanesrotate, with the result that a couple is. applied, tending to turn theframe 3 on the pivot-s4, 4. The distance it of the centre of gravity ofthe system carried on the ivots 4, 4, below the line of. the pivots isadjusted in accordance with the equation M Vh=lw, where M, V, I and a)have the meanings already specified.

As already explained, the direction of motion of the vehicle and thedirection of spin of the gyroscope being those indicated by the straightand curved arrows, respectively, the gyroscope keeps time with thevehicle when s00 e about the pivots 4', 4', and this causes 1 the latterturns, and the frame 3 maintains other side of the vertical, thecontactmaker As the frame oscillates from one ex treme position to theextreme position on the I 19 moves from the central osition to one ex--tremity of its range and ack again to the central position. When the'contactmaker leaves the central position,'the motor 6 comes into actionand the. vanes apply to the frame 3 a couple in the direction opposed tothat in which it is turning on the pivots 4, 4. When the contactmakercrosses the central posivention in which the necessity for a commutatorand brush is avoided. A small motor casing, leaves the system in a lineand in a 6*, to the spindle of which are attached vanes 8, 8, 8', 8 isattached to the frame 3 by means of vertical pivots 2 as shown. Thegyroscope 1 is attached to the frame 3 by means'of vertical pivots 2,after the manner illustrated in Fig. 4. Carried by prolongations of theupper pivots 2, 2 are arms 17 and 19'. The arm 17 has a bifurcated endengaging a small wheel '21 rotatably mounted on vertical bearingsprovided at the end of the arm 19. When the axis of the gyroscope liesathwart the frame 3, the arms 17 and 19 are in line and parallel tothe'frame 3, which frame, as already explained, lies fore and aft withrespect to the vehicle. The motor runs continuously and when the arms 17and 19 are in'line, the rotation couple, due to the passage of the vanesthrough the air, is in the plane of the frame 3, or in a. parallelplane, and thus exerts no moment about the fore and aft pivots whichattach the frame 3 to the moving vehicle. When the gyroscope 1 turns onthe pivots 2, the motor 6 is forcibly turned on the pivots 2 and astabilizing couple is a plied to the frame 3. By making the arm 1? longin comparison with the arm 19' a. small movement of the gyroscope bringsabout a relatively great movement of the motor and brings into existencean appreciable stabilizing couple. I

- Figs. 7 and 8 show, in plan and elevation respectively, a form of theinvention in which the stabilizing or damping couples are applied aboutthe fore and aft pivots 4, 4 as a consequence of the fact that when thegyroscope turns on the pivots 2, 2 a jet of air, derived 'from theperiphery of the gyroscope direction which results in a couple beingapplied about the fore and aft pivots. Attached to the frame 3 are twopipes 17' and 18 (these are not shown in Fig! shaped as shown. Attachedto the perip er roscope casing is a pipe 16, and tom this issues a jetof air at high speed. When the gyroscope is in the central position,that is, when its axis lies athwart the frame 3, the

of the jet is projected through a s provided between the pipes 17 18. enthe. gyroscope turns on the vertical pivots 2, 2 the pipe 16 movesrelatively'to' the frame 3, and the jet is projected intoone or'otherofthe pipes straining or stabilizing couples, are applied a to the systemabout the pivots 4, 4.

In Fig. 9 is shown inwelevation a further 17 and 18, anduisdeflectedthrough 90 and means of providing for the production of stabilizincouples. Attached .to the periphery o the gyroscope casing are two pipes16 16 one only being shown in the figure. These terminate in nozzles 20,20, which are directed at right angles to the frame 3. Attached to aprolongation of one of the pivots 2, 2 is an arm 13 terminating in acontactmaker 19 arranged to move freely on the commutator 15. Thiscommutator consists of two plates or strips of conducting materialseparated by a strip of. insulating material, as

already described. Attached to the tram 3 1 i are two electro-magnets21, each of whic is adapted, when energized, to attract a piece of softum 22, carried atone end of a rod pivoted at 23 to a pillar 24, or theequivalent. To the other end of'each rod is attached a screen 25, andeach rod is weighted so that normally. it lies with the screens in frontof I the nozzles 20, 20. When the gyroscope is in the central positionthe contactmaker rests on the insulating strip, with the result that thescreens lie' in front of the nozzles. When the gyroscope turns on thepivots 2, 2, current is passed through the coil of one or other of theelectro-magnets with the result that the corresponding screen is liftedand a jet of air leaves the system in a direction perpendicular to theframe 3, and the nozzles eing at a considerable distance below the lineof the pivots 4, 4, this results in the application to the" system of adamping or stabilizing couple. Y

In Fig. 10 is shown in elevation a still further means of damping outoscillations of the gyroscope which is convenient in cases wheretwo-phase or. three-phase alternating current is employed for drivingthe gyro scope or gyroscopes. The gyroscope 1 is pivoted, as before, tothe frame 3 by means of vertical pivots 2, 2. On a prolongation of oneof the pivots 2, 2 is an arm terminating in a wheel or roller whichengages a electro-magnets,

the centre of each disc is a hole of considerable diameter, and thediscs surround the poles (which "are elongated) of the electromagnets.When the gyroscope is central with respect to the frame 3, the contactroller rests on the insulating stri and no current is supplied to thecoils o the electro-magnets; but when the gyroscope turns, with respectto the frame 3, on the pivots 2, 2, alternating current obtained fromone of the phases of the supply available for driving the gyroscope,passesthrough the coil of one of the and the surrounding disc 7 isstrongly repelled. The arran ement is such that the repelling force resuts in the application to the frame 3 of a restraining or stabilizingcouple.

.- 3 o di dvantarre from which the arrangements so far described sufferis that where the speedof the vehicle is relatively small the amount ofgravity control which must be .Q'giyen to the system with respect to thefore and aft pivots is large, and the natural perlod of marine craft theamount of gravity coni which the of the roscopic pendulum is conseuently, small. he arrangements are valua le for use in aeroplanes andairships, but in the case trol .necessary, in order that the equation MVh==l 0) may be satisfied renders the natural period small, anddiminishes the value of the arrangements.

In Fig. 11 is shown an arrangement in disadvantage is overcome. A maingyroscope 1 is attached, as before, to a vertical frame 3 by means ofvertical pivots 2, 2. One of these pivots is prolonged, and to theprolongation is attached an arm 13 which terinsulating material.

minates in a contact-wheel or roller 19 adapted to engage acontact-making device consisting, as a ready described, of twoconducting strips separated by a narrow strlp of The gyroscope iscentralized by means of springs 9., 9 after the .3, by means 0 a wormaprolongation of one of the ment the gyroscope 1 may be set with its axisof spin making any desired angle with a normal to the plane of the frame3.

. As before, the frame 3 is attached to fore and aft uprights 5, 5, bymeans of pivots'4, 4. Carried on the frame 3 is a'reversible motor 6 onthe spindle of which is mounted a system of vanes 8 adapted to apply tothe frame 3 a con la in a plane perpendicular to the line of the ore andaft plvots 4, 4. This motor is controlled by the contactmaker 19 and thecommutator 15 after the manner already described. When the gyroscope 1leaves the central POStlOD, the contactmaker supplies current to themotor which rotates in'the direction which results in there beingapplied to the frame 3 a couple tending to'return the gyroscope 1 to thecentral osition.

If the frame 3 is defiecte with respect to the vertical, and the deviceis then left to itof the restraining couples applied to the gyrosco e 1by the vanes 8 8.

ow, suppose that the device is set up on a moving vessel with the pivots4, 4 lying fore and a Suppose the gyrosco es 1 and 1' 'to be identical,the gyroscope 1 being set so that its axis of spin makes an angle 0 withthe normal to the plane of the frame 3. Let r the directions of spin ofthe two gyroscopes be as shown by the curved arrows, and the directionof motion of the vessel that shown by the straight arrow. Suppose nowthe vessel to turnv to port at angular speed 11. The gyroscope 1' isturned forcibly at thisangular speed and there is applied to the frame3, and consequently to the gyroscope 1, a couple whose momentis "I 0)cos 0 where I is the moment of inertia of the ywheel of either gyroscopeand w is the angular speed of the flywheel of 1'. The direction of thiscouple is such as to cause the gyroscope 1 to turn on the pivots 2, 2 inthe sense of 1 1. If M is the mass of the system carried on the pivots4, 4, k the distance of the C. G. of the system below theline of 4, 4,and V is the speed of the vessel, the so-called centrifugal coupleexperienced by the frame is MVh p. This couple has the sense of theformer couple, and causes the gyroscope 1 to turn to port. If theangular speed 0 the gyroscope 1 is also a), we have for the angularspeed 0 at which it turns on the pivots 2, 2 L

and if I w (1cos'0) =MVh, Q=p and the gy- .roscope 1 keeps time with therame 3, and

there is no disturbance as a consequence of the turning motion.

If the device 1s set up on a'vehicle with the pivots 4, 4 lying athwartthe vehicle, then the device is available to define the verticalprovided that 0= 0. The angular momentumlying athwart the frame due tothe compensating gyrosco eis numerically equal to that of thestabilizing gyroscope.

It is easy to show-that if the condition just investigated is fulfilledby the combination of gyroscopes the device has the very importantproperty that if the frame 3 is deflected lu l with. respect to the trueverticah'the device comes to rest with the frame 3 in the true vertical,and the axis of the gyroscope 1 lying athwart the frameS. The restingposition of the frame 3 is, in fact, the true vertical, even when thevehicle on which the device is mounted is turning.

If the direction of motion of the vessel is reversed, the directions ofthe gyroscope couple (due to the compensatin gyroscope 1) and of thecentrifugal coup e are reversed, and the compensation holds good.

When the speed of the vehicle is changed, it is necessary to alter bymeans of the worm and wheel adjustment, or to alter h by moving thecompensating weight up or down by means of the screw adjustment.

t will readily be seen that the gyroscopes 1 v and 1 need not beidentical. There must be tached to the frame 3 by provided, lyingathwart the frame 3, and forcibly turned with the frame a component ofspin I (0 such that I w=I w +MVh.

The compensating gyroscope may be atmeans of fore and aft ivots 32, andcentralized with respect to the ame b vertical springs 33, 3,3 and stops34', 35, as s own in Fig. 12. So mounted it acts after the manner ofGilberts bary-gyroscope, and is available to indicate that the vehicleis turning. The movement of the gyroscope 1 relatively to the frame maybe utilized to make electric contacts through the medium of the stops34, 35 and the making of such contacts may be utilized for a variety ofurposes, notably for steering.

alternative arrangement consists in rotating the main gyrosco e 1 in thecounterclockwise direction, an the compensating gyrosco e 1' in theclockwise direction as viewed mm the starboard sideof' the vehicle."

If there is no disturbance of the system brought about by turning of thevehicle, and the main gyroscope is to keep time with the frame 3 durinthe turning motion, we have (of-I (d I claim 1. In combination, a movingbody, horizontal pivots extending in the normal direction of movement ofsa1d body, a vertical frame movable about said pivots, a gyroscope ind acouple to the casmg of said gyroscope 1n cludin a casin attached to saidframe an pivota y mova Is on a vertlcal axis, the axle of spin of saidgyroscope being horizontal and normally athwart the plane of said frame,means for centralizing said gyroscope with respect to said frame, meansfor adjusting the amount of gravity control ossessed by said frame sothat the moment 0 momen-- tion of movement of said body, a verticalframe mounted on said pivots, a gyroscope including a casing attached tosaid frame and pivotally movable on a vertical axis, the axis of spin ofsaid yroscope being horizontal and normally at wart the plane of saidframe, means for centralizing said gyroscope with respect to said frame,a weight attached to said frame,- a screw rotatable to raise and lowersaid weight, and means for applying couples about said horizontal pivotswhereby said gyroscope is stabilized. I

3. In combination, a moving body, horizontal pivots extending in thenormal direction of movement of said body, a vertical frame mounted onsaid pivots, a gyroscope attached to said frame and pivotally movable ona vertical axis, the axis of spin of said gyroscope being horizontal andnormally athwart the plane of said frame, spring means for centralizingsaid gyroscope with respect to said frame, a weight attached to saidframe, means for raising and lowering said weight and airimpelling meansunder control of said roscope for applying couples about said orizontalpivots.

4. In combination, a moving body, horizontal pivots extending in thenormal direction of movement of said body, a vertical frame mounted onsaid pivots, a gyroscope including a casing attached to said frame and aspinning body within said casing, the axis of spin being horizontal andnormally athwart the plane of said frame, a weight attached to saidframe, a screw rotatable to raise and lower said weight, and means forapplying a couple to the casing of the gyro-' scope in the lane of thespinning body. 5. In com ination, a moving ody, horizontal pivotsextending in the normal directhe plane pf the spinnin body.

In testimony whereof I have signed my I name to this s ecification.

AMES GORDON GRAY.

